Effect of Carbonization Temperature on Electromagnetic Wave Absorption Properties of Mo₂C/C Nanocomposites

The CuMo-metal-organic frameworks （MOFs） precursor was prepared by room-temperature stirring method, and then was subjected to carbonization at different temperatures （900, 1 000, and 1 100 ℃） to prepare Mo₂C/C composites. The effects of carbonization temperature on the electromagnetic wave absorption properties of the composites were studied by analyzing the microstructure, phase composition, and electromagnetic parameters. The results show that the flake-structured Mo₂C/C composites were successfully synthesized at different carbonization temperatures, and nano-sized Mo₂C particles embedded within the carbon skeleton. At the carbonization temperature of 900 ℃, an impurity phase of MoP appeared in the composites. When the temperature increased to 1 000 ℃, the MoP phase disappeared, the composites were further coalesced into a polyhedral lammellar structure. When the carbonization temperature increased to 1 100 ℃, Mo₂C nanoparticles were precipitated on the surface of the lammellar structure. With the increase of carbonization temperature, the electromagnetic wave absorption and loss properties were first enhanced and then weakened. When the carbonization temperature was 1 000 ℃, the composite exhibited an effective absorption bandwidth of 3.1 GHz at a thickness of 2.5 mm and a minimum reflection loss of −20.8 dB, demonstrating a optimal electromagnetic wave absorption performance.